Electrical communicating system



Sept. 8, 1925.

C. R. GAUTHIER ELECTRICAL COMMUNICATING SYSTEM Filed Nov. '22,- 1919 4 Sheets-Sheet l IN Vf/V 70/? mg, MW

C. R. GAUTHIER ELECTRICAL COMMUNICATING SYSTEM Sept. 8, 1925.

4 Sheets-$116M; 2

Filed Nov. 22, 1919 Sept. s, 1925.

C. R. GAUTHIER ELECTRICAL; COMMUNICATING SYSTEM Filed Nov. 22, 1919 4 Shee'ts-Shee't 5 3 9Q .32 n WW I u \I I N Mg m2 r [L v .f i R Sept. 8, 1925. 1,552,919

c. R. GAUTHIER ELECTRICAL COMMUNICATING SYSTEM Filed Nov. 22, 1919 4 Sheets-Sheet 4 9x a O /N VfN TOR Patented Sept. 8 1 9 25.

. UNITED STATES PATIENT- j OFFICE;

enosnfv a sacrum, or 'miw'voax, n. 1,488161103 r wnmn mm, mc.,.or

raw 101m, 1:. z, A conaomrrox or nmwm nLmc'rnIc'AL commce'rnrq exam Application filed mam a, me. Serial Io. 340,020..

To'all whomitmay concern."

Be it known that I, CROSBY R. Gamma, a citizen of the United States, residigg at New York city, in. the county of New ork, State of New York, have invented certain new and useful Improvements in Electrical Communicating Systems, of which the following is a specification.

This invention relates, in general, to elec- 10 trical signaling systems such as telephone and telegraph systems, and is directed more particularly to such a system wherein both radio and metallic line transmission are em-.

ployed. Y One object of the invention is the provision of an economical and reliable system whereby telephone or telegraph communica tion can be established and maintained between moving vehicles and distant statlonary points or between distantly s'eparatedmoving vehicles, as for example, two railroad trains.

Another object of the invention is the provisionin a telephone or telegraph system of means whereby a radio station can be selectively and operativelyconnected toa metallic transmission line under the control of a distant operator. a

- Still'another object of the invention is the provision of a telephone system which W111 permit telephone subscribers in distantly "separated localities to transmit speech and the like through the medium of a plurality of distantly separated radio stations simultaneously.

One of the principal features of the invention relates to the provision of a telephone system wherein a plurality of radio stations and a plurality of telephone exchanges a e situated at intervals along and operatively associated with a metallic transmission line and wherein means-are provided for transv mitting signals over the transmission line and into the ether from any of the tele hone exchanges through the medium of al the radio-stations simultaneously. Another of the principal features of the invention consists in the provision of a system for transmitting signals to and from moving vehicles, as for example, between distantly separated trains, or between atrain and a distant station. According to this feature of the invention there is preferably provided one or more metallic transmission lines along the route of the vehicle, as for in-- stancef along a railroad track. A source of high requency current on the vehicle or ve- -hicles, means for suitably modulating the high frequency current in accordance with the-voice or ot er signals also on the vehicle or vehlcles, and means for impressing the modulated high frequency current on the transmission line whereby the signals are transmitted over. the transmission line to the other vehlcle or distant station. By such an arrangement it is practicable to provide long distance telephone or telegraph'servicefor passengers and operators on moving trains and other vehicles without employing long distance radio transmission, thus securing at least semi-private communication and eliminating toa large extent the uncertainties inherent in long distance radio transmission.-

Still another of the principal features of the invention relates to an arrangement whereby a radio station'- or stations can be selectively connected to a metallic transmission line or lines under the control of a distant o erator. Thisis.ar:comp ished,preferably,

or are operable over a circuit extending to a distant control station, as for instance,- a

telephone exchange.

A still further feature relates to the provision of an arrangement whereby the operative frequency or wave length of a radio station or the frequencyof a source ofcarrier current can be controlled over a metallic c1rtherefore do not wish to be limitedexcept as indicated by the appended claims.

' The embodiment of the invention which has been chosen for a detailed description is a telephone system particularly adapted for use on railroads and which may be connected in this i with the usual telephone systems such as the Bell system, thereby providing telephone service for passengers and trainmen on moving trains. Incidentally the invention is also adapted for train'dispatching service.

This specific embodiment ofthe invention comprises a plurality of radio stations distributed along a railroad at relatively short intervalsfeach radio station being equipped with radio transmitting and receiving apparatus; one or more trunk lines extending along the railroad, at least one end of which connects with an operating or control station (which may conveniently be a telephone exchange) and means under the control of an operator at the control station whereby the radio apparatus at each of the radio stations can be connected to and disconnected from the trunk line as required. The trains on the railroad are equipped with radio transmitting and receiving apparatus and the control station is equipped with essential telephone apparatus.

Telephone communication is established between parties on the trains and the operator at the control station through the medium of the operators telephone apparatus, the trunk line, the transmitting and receiving apparatus at the radio stations and the transmitting and receiving apparatus on the trains.

The transmitting range of each radio station is preferably quite short. It need be only a trifle more than half the distance between radio stations. In other words, if the radio stations are spaced five miles apart, the transmitting range of each radio station need be and is preferably only a trifle over two and one-half miles in each direction.

Communication is established through the medium of any one radio station, only while a train is within the range of that station. When a train passes out of the range of one radio station and into the range of a succeeding radio station, the first radio station is disconnected from the trunk line and the sec- 0nd radio station is connected thereto, etc.

The advantage of using a plurality of radio stations equipped with short range transmitting apparatus will be obvious to those skilled in the art. Interference is largely eliminated by this system and communication can be established over long distances. The ossibility of meassages being intercepted by stations for which they are not intended is also reduced to, a minimum by the use of short range apparatus. The transmitting apparatus carried by the trains is of course, also of the short range variety.

Another feature of this system comprises the use in connection with the aforementioned parts of the system, of a listening-in line extending along the railroad, at least one end of whichconnects with a control station. The receiving apparatus at each idle radio. station is normally connected to the listening-in line and the controlling operators telephone set can be connected thereto. The object of the listening in line is to provide means whereby parties on trains on the railroad can call the controlling operator, and whereby the controlling operator can talk through the medium of several radio stations simultaneously whenever it becomes necessary to locate a train. Upon receiving a call from a train the controlling operator selects an idle trunk line and connects thereto, the radio station nearest the train. The provision of a listening-in line reduces the number of trunk lines necessary on a railroad where there are a large number of. trains travelling at the same time. For example, if there were a maximum of say twenty trains travelling at one time over a certain railroad, in order to provide communicating means for every train, without using the listening-in line it would be necessary to provide twenty trunk-lines. But the probabilities are that not more than five of these trains would require a connection at any one time and therefore five trunk lines and a listening-in line would be sufficient.

Another feature of this s stem is a wavelength changin device. T e radio apparatus is preferab y arranged to operate on a number of different wave lengths. In the drawings accompanying 'this specification, the radio circuits are shown arranged for operating on four different wave lengths.

Of course, any desired number of wave lengths can be provided for.' The wave length changing device comprises an electromagnetic step b step mechanism co-operating with a num er of movable switch members, the energizing circuit of the step by step mechanism being operable by the operator at the control station. In the particular arrangement described herein, this mechanism is operable only when the radio station with which it is associated is connected to a trunk line. When a radio station is disconnected from a trunk-line it is thereupon automatically' connected to a listening-in line and the wave-length changing mechanism is automatically restored to 1ts first or normal position. Thus, every idle radio station is set to operate on the same wave-length. This is desi nated the listening-in 'wave length. The ra i0 apparatus at each radio station is preferably a justed to operate on a corresponding wave-length for each corresponding position of the wave length mechanisms. As reviously stated, means are employed whereby the various radio stations can be connected to and disconnected from a trunkline as required.

Assuming that communication has been established with a train, as it proceeds along the road, one radio station after another will be successively connected to and disconnected from a trunk line. The preferred means whereby these connections and disconnections are accomplished comprises the use of electro-magnetic selector mechanisms, the operation of which is under the control ll l of an operator at the control station. The selector mechanisms or, briefly, selectors operate on combinations .of electrical impulses and in the circuit herein described the selectors are of the biased polarized typeQthat is they operate only on combinations of unidirectional electrical impulses and each selector will respond effectively only to impulses flowing in a definite direction through its coils. Currents flowing in opposite directions .througha circuit are sometimes designated, for convenience, as positive and negative currents and this designation will be used hereinafter. Each selector, then, will respond only to current impulses of a definite polarity, that is, positive or negative, and will not be affected by impulses of opposite polarity.

The selectors at every alternate radio station operate on impulses of like polarity. For example, considering four succeeding radio stations A, B, (l and D, the selectors at A and C will respond to impulses of like polarity, say positive impulses, and the selectors at stations B and D will respond to impulses of like polarity, but of the polarity opposite to that to which A and C respond, that is B and D will respond to negative impulses. If it is desired to connect radio station A to a trunk line, a definite combination of positive impulses are sent over the selector circuit and the selector at A will operate and close its local circuit, thereby connecting the radio apparatus at A to the trunk-line and simultaneously disconnecting the radio apparatus from the listening-in line. As soon as a communicating train has passed out of the normal range of A, it is necessary to connect B to the trunk line and disconnect A therefrom. The selector at B is operated by sending out a definite combination of negative impulses and as stated before the negative impulses will have no effect on the selector at A. Therefore B is connected to the trunk line before A is disconnected therefrom. Immediately after the requisite combination of negative impulses to operate the selector at B have been sent out, one additional positive impulse is sent out and this operates the selector at A to restore it to normal. Upon the restoration to normal of the selector at A. that station is disconnected from the trunk-line and connected to the listening-in line. By this arrangement it will be seen, a. continuous connection is maintained, there being no interruption due to transferring from station to station. Selectors operating on combinations of electrical impulses are well known in the art. For a description of such a. selector reference is made to United States Patent 1,24 l,54 l to Charles S. Rhoades, Jr.

Impulse sending devices are also Well known in the art and require no description.

. A modification for an impulse sender for use with this invention Wlll be described 1n the detailed description hereinafter. This modification affords a means whereby a spring operated impulse sender can be wound up and restrained from operating until released by an electromagnetically operated catch. By this provisionwhen an operator has established a connection with a train, she can wind up theimpulse senders corresponding with several succeeding radio stations and they will be released automatically when the train enters the range of the respective radio stations. Thereby, the operator is relieved of the necessity of watching signal lamps indicating the passage of the train from section to section.

An installation in accordance with this invention would ordinarily include a number of control stations. For example, an installation between Albany and Buffalo would be likely to include control stations at Albany, Utica, Syracuse, Rochester and Buffalo. Assuming that a train is proceeding from Albany to Buffalo, from the.- time it leaves Albany until it reaches Utica, conversations with that train can be handled by the operators either at Albany or Utica as required. If, for instance, a passengeron the train wishes to talk with a telephone subscriber in New York, the call will be handled by an Albany operator, but if the passenger wishes to talk with a telephone subscriber in Buffalo, the call will be handled by a Utica operator. Considering the first case, that is a connection between the train and a New York telephone subscriber, the call will be handled by an Albany operator as long as the train remains in the division between Albany and Utica, but if the communication continues after the train passes Utica, then the control of the operation will be transferred from Albany to Utica and the latter operator will continue to handle the call until the train reaches the next control station, namely, Syracuse, when lUU an operator at the latter station will take it up.

To establish communication between two trains in the same division, that is located between succeeding control stations, the operator appropriates two idle trunks in that division and connects the two together by. means of .a suitable cord circuit. The radio station nearest one of the trains is then connected with one of the trunks, and the radio station nearest the other train is connected to the other trunk. Where the trains are in different divisions, the trunks are extended through the control station or stations, as the case may be, by means of the cord circuits. Where the trains are in adjacent divisions, the operations involved in connecting the radio stations to the trunks and changing connections as the trains protrol stations.

coed may be controlled b one operator, but where the trains are in distantly separated divisions, the operators at each of two con trol stations will be required to establish and maintain the connections.

Any suitable radio transmittingand receiving circuits can be used with this invention. The. transmitting circuit shown in the drawings accompanying this specification is based on that shown in United States Patent No. 1,273,789 to lVilliam C. White and the receiving circuit is one well known in the art. No detailed description therefore, will be required for an understanding of these circuits.

Substantially the same radio circuits as are provided. at the radio stations would also be provided on the trains except for obvious modifications, as, for instance, the remote control wave length changing arrangement would not be provided on the train. It is therefore thought that there is no necessit-y for showing the radio circuits for use on the trains. No provision is shown for amplifying the received signals, but it will be obvious that amplifiers can be used if required.

Provisions are shown in the circuits for operating the radio transmitting apparatus and the radio receiving apparatus, alternately. This provision comprises a transmitting and receiving relay, one at each radio station, the energizing circuits of which are controlled by the operators at the con- The transmitting and receiving apparatus is arranged to operate alternately in order to prevent the well known howling effect which might otherwise result. The transmitting and receiving relay will be hereinafterreferred to as the T 8: R relay.

- Referring to the drawingsFig. 1 is a fragmentary general arrangement showing two radio stations, with associated antennae and selector apparati; two trunk-lines; a listening-in line; a control stationconnecting with the lines; a railroad track with a passing train indicatedthereon in dotted lines; and lamp signals at the control station for indicating the positions of trains. Many of the details are omitted from this figure.

Fig. 2 is a circuit diagram of a complete radio station with connections to trunk lines, listening-in lines and lines serving the & R relays, selectors and wave length changing mechanisms.

Fig. 3 is a fragmentary circuit diagram showing a trunk line connecting two control stations and impulse sending devices associated with one of the control stations together with a circuit arran ement illustrating the operation of one se ector at a. radio station. The operating circuit for a wave length mechanism and a T & R relay are here shown. .Jacks forming terminals of the trunk and signal lamps for indicating the operative condition of the trunk line and a talking cord circuit at one of the control stations are shown. A trunk leading from one of the control stations to a local telephone ofiice and part of a cord circuit at the local telephone ofiicc are also shown.

Figure 4, illustrates the modification for the impulse sender hereinbefore referred to.

Figures 5, 6 and 7 show the wave-length changing mechanism of which Figure 5 is a plan view of one of the radial switches.

Figure 6 is a side elevation showing five radial switches, arranged in superposed relation to each other.

Figure 7 is a sectional view on line 7 7 of Figure 6, showing the electro-magnetic step by step mechanism whereby the rotatable ratchet member is driven.

Before embarking upon a description of the operation of the system, a brief description of the mechanisms illustrated in Figs. 4, 5, 6 and 7 will be given.

There is represented in Fig. 4 an ordinary impulse sending key of the type employed in train dispatching systems except that a simple provision is shown for rendering the operation of the key semi-automatic. The disc 146 is integral with the winding handle 145, and is provided with a lug 147, which bears against a shoulder of armature 148 and is thereby prevented from unwinding. The key is wound by turning in the direction indicated by the arrow, and in unwinding turns in the opposite direction. It will be quite clear from the drawing that when electromagnet 149 is energized, armature 148 is attracted, and the key is thereupon free to unwind. The impulses are sent while the key is unwinding.

The wave length changing switch of Figs.

5, 6 and 7 comprises five contact wiper arms' 13, 99, 100, 101 and 102, each of which is operatively and individually associated with a set of four fixed contact points. All the contact wiper arms are insulatively mounted on a common rotatable shaft, to the end of which is secured a ratchet member 127. The mechanism for operating the ratchet member comprises a stepping pawl 125, which is pivotally attached to the armature 160 of the stepping magnet 109. 126 is a holding awl, and 119, 120 are releasing magnets.

ach energization of stepping magnet 109 will effect a forward movement of stepping pawl I25, and will accordingly step ratchet member 127 forward. The latter is held in any of its forward positions by holding pawl 126, and may be released by energization of electromagnets 119 and 120, whereupon it is restored to normal, together with thdl contact wiper arms, by the restoring spring 128. It will be understood that the several contact wiper arms engage successive fixed contacts for each successive forward step of the ratchet member.

In the following description of operation of this invention, it will be assumed that a calling arty on a train running from Albany to ufl'alo wishes to communicate with a telephone subscriber in Albany. The train is situated somewhere between Albany and Utica and proceeding toward the latter city. Referring to Figure 1 of the drawings, 1 is the train; 2 and 3 are sections of track insulated at point 4; 5 is the control station at Albany; 6 is the antenna associated with radio station A. Radio station B is similar in all respects to radio-station A and will therefore require no separate description. 135 is the radio apparatus at radio station A. 17 is the T & R relay the contacts of which are shown in transmitting position. and 131 are two trunk lines and 26 is a listening-in-line, terminating in jack 27. 21 and 24 are relays controlling the connection of the radio apparatus with the listening-in line. 59 and 110 are relays controlling the connection of the radio apparatus with the trunk-lines 35 and 131 respectively. 49 is a relay for cutting ofl selector 36 and 60 is a relay for cutting off selector 64. All the above relays except relay 17 are in local circuits controlled by selectors 36 and 64 respectively.

The train 1 being in section 2 of the track and therefore within the range of radio station A, the call from the train is picked up by the antenna 6 and receiving apparatus R at radio station A. Referring to Fig. 2, the antenna circuit for the listening-in position consists of antenna 6, inductance 7. condenser 9, switch 13. inductance coil 8 and ground. The received signal is induced into the coil 14 of the receiver circuit R rectified and somewhat amplified by said receiver circuit and induced in the form of Voice modulated current into the secondary 16 of transformer- 15 which transformer may or may not be provided with a core of magnetic mate-ial. The circuit from secondary coil 16 to the listening in line 26 comprises conductors 18 and 34, contacts 19 and of the .T & R relay 17, this relay being at the time de-energized. conductors 136 and 137, contacts 20 and 31 of relay 21. conductors 22 and 30. contacts 23 and 29 of relay 24 and conductors 25 and 28. The listening in line 26 terminates in jack 27 and the controlling. operators telephone is connected to that jack.

The operator upon hearing the call and determining the location of the train, selects idle trunk line 35, and plugs into jack 71 with plug 69 of cord circuit 70 (see Fig. 3). She then winds the impulse send-er 38 and releases it. The contact 39' of the impulse sender 38 is thereupon operated to send out a definite combination of positive impulses operating selector 36 at radio station A. The circuit from impulse sender 38 to selector 36 comprises contact 39, conductor 41, battery 40, conductor 57 to point 56, conductor to point 51, conductor 53, armature 52 of relay 49 and its contact, conductor 165, winding of selector 36, conductor 50, armature 48 of relay 49 and its contact, conductor 47 to point 46, ring side of trunk line 35 tov point 45, conductor 44 to point 43, conductor 42 to contact 39. Contact 58 is closed by the operation of selector 36, and relays 24, 59 and 60 are thereupon energized, their circuits being closed bycontact 58.

Energizing relay 60 breaks contacts and 66 thus disconnecting selector 64, thereby preventing its operation. Energizing relay 24 breaks contacts 23 and 29, disconnecting the radio apparatus from the listening in line and energizing relay 59, closes contacts 62 and 93 connectin the radio apparatusrto the trunk line. circuit of step by step magnet 109 of the wave length mechanism, and since that contact is nowclosed the wave length mechanism can be operated by the controlling operator.

The circuit whereby the controlling operator operates the wave length mechanism comprises switch contact 108 at the Albany control station, conductor 118 to point 117, conductor 116, electromagnet 109, conductor 115 to point 166, conductor 87, contact 62 of relay 59, conductor 77 to point 78, ring side of trunk line 35 to point 113, conductor 112, battery 111, and contact 108. Each time contact 108 is closed, electromagnet 109 is energized and the wave length switches are advanced one step. A suitable switching mechanism would ordinarily be provided for operating contact 108 the required num-' ber of times for any desired wave length.

The circuit for operating the T & R relay is controlled by switch contact 82 and comprises battery 81. conductor to point 79, ring side of trunk line 35 to point 78, conductor 77, contact 62 of relay 59, conductor 87 to point 76, conductor 75, T & R relay 17, conductor to point 84, conductor 83 to contact 82. Closing contact 82 energizes T & R relay 17 which closes contacts 72, 73 and 74, thus connecting the transmitting circuit T to the trunk line 35. With T & R relay 17 energized, the circuit from primary coil 89 of transformer 90 to trunk line 35 comprises conductor 88, contact 74, conductor 87 contact 62 of relay 59, conductor 77 (fontact 62 is in the to point 78 on the ring side of the trunk line,

Referring to the radio transmitting circuit T shown inv Fig. 2, it will be noted that condenser is connected in circuit by virtue of switch member 99 being in the first or listening in osition. Vhen switch member 99 is shifted to second, third, and fourth pos1- tionsycondensers 96, 97 and 98 respectively are connected into the circuit. Only one of the condensers is in circuit at a time. Likewise, a different number of turns of coil 103 are connected in circuit for each position of switch member 100. Coil 103 and the condensers 95, 96, 97, and 98 constitute the oscillating circuit of the transmlttcr and by the use of condensers of various capacltles together with various numbers of turns of the coil 103, the natural frequency of this oscillating circuit, and consequently the wave length, is varied. The wave length of the receiving circuit is likewise varled through the medium of the condensers 104, 105, 106 and 107 and the wave length of the antenna is varied by means of condensers 9, 10, 11 and 1.2. The wave length of the transmitting circuit, receiving circuit and antenna circuit is of course varied simultaneously.

. The train being in track section 2, relay 138 is energized by battery 139 and the local circuit of signal lamp 140 is closed thus lighting that lamp. Signal lamp 140 indi cates to the operator the location of the train. When the train passes out of section 2, into section 3, and therefore out of the range of radio station A, and into the range of radio station B, signal lamp 141 will be lighted and lamp 140 will be extinguished. The operator is thus notified to transfer the connection from radio station A to radio station B, and this is accomplished by operating impulse sender 142, sending out a combination of negative impulses. Negative impulses will not affect the selector of radio station A, as it is designed to operate only on positive impulses, and consequently the radio apparatus at radio station B will be connected to trunk line 35, while that at radio station A still remains connected thereto. However, after impulse sender 142 has finished sending its combination of negative impulses, the lug 143 will cause the operation of contact 144, thereby sending out one positive impulse which will operate to return selector 36 at radio station A to its normal position. Radio station A will thereupon be disconnected from trunk line 35 and connected. to listening in line 26. Relay 59 being deenergized by the opening of its circuit, its armatures will be restored to norm-a1 breaking contacts 62, 93 and 122. But before contact 122 breaks, contact 123 will make thus momentarily establishing a circuit through release ma ets 119 and 120 of the wave length mec anism, and battery 124. The

holding pawl 126 and ste ping pawl 125 will be thereby released, an the ratchet 127 together witlfswitch members 13, 99, 100, 101 and '102 will be restored to normal, that is the listening in position.

The electromagnets 149 of the impulse sender release mechanisms Fig. 4 would ordinarily be connected in the circuits of signal lamps 140 and 141, and would be energized upon a train entering the corresponding sections of the track. 7 Referring to Fig. 3 it is seen that trunk line 35 interconnects two control stations and terminates in a jack at, each end. Signal lamps and associated relays are shown for indicating busy lines. When plug 69 is inserted in jack 71 a circuit will be established from battery 152 of cord circuit 70, at Albany through relay 151, at Utica, energizing that relay; causing its armature to be pulled up closing the circuit of signal lamp 150. Lighting of signal lamp 150 will indicate to the Utica operator that trunk line 35 is busy. When the train approaches Utica the Albany operator will call the Utica operator on an order wire or by other means not shown and ask the Utica operator to take over control of the connection. The Utica operator will insert plug 154 into jack 153 and the plug at the other end of the cord circuit 158, into the jack of a succeeding trunk line extending to Syracuse, the next control station. The operation is then a repetition of that which has been previously described.

N o flash back signal is shown for indicating to the Albany operator that the conversation has been completed, and the connection may be taken down, but such signalling arrangements are old in the art and will be obvious. In the circuits described only one radio station is connected to the same trunk line at one time, but if desired the circuits can be readily modified so that more than one radio station can be connected at one time to the same trunk line.

In .the event that an operator wishes to communicate with a train in her division the position of which she does not know, she will plug her telephone set into the listening-in line jack and operate the T & R key associated therewith, thereby connecting the transmitting apparatus at all the radio stations in her division or one of her divisions, as the case may be, to the listening-in line, and she may then speak through the medium of all the so-called radio stations simultaneously and ask for the position of the desired train. Upon receiving the necessary information from an operator on the wanted train, she will transfer the connection to an idle trunk and proceed as previously described.

Two trunk lines 35 and 131 respectively are shown in Figs. 1 and 2. Two selectors 36 and 64 are shown at radio station A,

co-operating with trunk lines 35 and 131 respectively and two relays 49 and 60 are shown co-operating with the selectors. When selector 36 is operated and contact 58 is closed, it will be seen that the circuit of relay 60 will be energized, and contacts 65 and 66 will be open cutting off selector 64. Likewise if selector 64 were operated, relay 49 would be energized cutting off selector 36. It is obvious that the functions of relays 21, 49 and 110 can be performed by a single relay and likewise the functions of relays 24, 59 and 60 can be performed by a single relay. Greater simplicity of illustration is accomplished. however, by showing three relays instead of one. Furthermore it is obvious that these relays can be entirely eliminated by the use of a selector designed to directly operate the contacts operated by these relays.

Where a system in accordance with this invention is utilized as a broadcasting systom, the automatic selectors at the radio stations may, if desired, be eliminated, and the radio apparatus can be connected directly to a transmission line or through the medium of plugs and jacks or the like. But itis preferable to'retain the selectors, as it may be desirable at times to broadcast through only one or two stations at a time. Where the specific arrangement shown and described herein is used for broadcasting purposes, either the listening-in line or a trunk may be employed as the medium for transmitting the signals from the control stations to the radio stations. The signals to be broadcasted may be transmitted from any of the control stations and into the ether through the medium of all the radio stations simultaneously.

The system herein described in detail is equally applicable with perhaps slight modifications for use in communicating with ships at sea and particularly ships running coastwise. If used in such a connection, the radio stations would obviously be located along the coast. It is also applicable, of course, for communicating with river-going vessels.

What is claimed is:

1. A signaling system comprising a plurality of radio stations situated at intervals, a transmission line multiply associated with said radio stations and means remotely operable whereby said radio stations can be selectively connected with said transmission lme.

2. A signaling system comprising a plurality of radio stations situated at intervals, a control station, a transmission line multiply associated with said radio stations and connected with said control station, and means operable from said control station whereby said radio stations can be individually connected to said line.

3. A signaling system comprising a plurality of radio stations situated at intervals, a control station, a line multiply associated with said radio stations and connected with said control station and selective means operable from said control station whereby said radio stations can be individually connected to said line.

4. A signaling system comprising a plurality of radio stations situated at intervals, a. plurality of transmission lines multiply associated with said radio stations and automatic selective means whereby said radio stations can be individually connected to any of said lines.

5. In a signaling system, a radio station comprising radio apparatus, a transmission line associated with said radio station and automatic selective means at said radio station whereby a terminal of said line can be connected to and disconnected from said radio apparatus.

6. A signaling system comprising a plurality of radio stations situated at intervals, a transmission line multiply associated with said radio stations, automatic means for selectively putting said radio stations into communicative relation to said line and means whereby a signal may be transmitted over said line to a selected radio station and re-transmitted from said selected radio station into the ether through the medium of electromagnetic waves.

7. A signaling system comprising a plurality of radio stations situated at intervals, a transmission line multiply associated with said radio stations, a control station associated with said line, means operable from said control station whereby any of said radio stations can be selectively put into communicative relation to said line, and means whereby signals can be transmitted from said control station over said line to any of said radio stations which may be in communicative relation thereto, and retransmitted into the other through the medium of electromagnetic waves.

8. A signaling system comprising a plurality of radio stations situated at intervals, a plurality of transmission lines multiply associated with said radio stations, said radio stations normally connected with one of said lines and disconnected from the other or others and selective means operable to disconnect any of said radio stations individually from the line to which it is normally connected and connect it to another of said lines.

9. In a signaling system, a radio station comprising radio apparatus, a transmission line associated with said radio station and selective means remotely operable whereby said radio apparatus can be connected to and disconnected from a terminal of said transmission line.

10. In a signaling system, a radio station comprising radio apparatus, a transmission line associated with said radio station, a control station associated with said line, selective means at said radio station operable from said control station whereby said radio apparatus can be connected to a terminal of said line.

11. In a signaling system, a radio station comprising radio apparatusya plurality of transmission circuits associated with said radio station and automatic selective means at said radio station whereby said radio apparatus can be putinto communicative relation with an of said lines.

12. In a signaling system, a radio station comprising radio apparatus, a transmission line associated with said radio station, a control station connected with said line, electromagnetic. tuning means at said radio station adapted to change the operating wave length of said radio apparatus, said tuning means operable from said control station, and a circuit for said tuning means including said transmission line.

13. In a signaling system, a radio station, comprising radio apparatus; means remotely operable, whereby said radio apparatus can be connected to and disconnected from a trunk line, and means remotely operable when said radio apparatus is connected to said trunk line, whereby the operating wave length of said radio apparatus can be varied.

14. In a signaling system, a radio station, comprising radio apparatus, means remotely operable, whereby said radio appa ratus can be connected to and disconnected from a trunk line, an electro-magnetic switching mechanism, remotely operable whereby the operating wave length of said radio apparatus can be varied, a circuit and a source of current for said electro-ma etic switching mechanism and means for interrupting said circuit.

15. In a signalling'system, a radio station comprising radio apparatus, a selector responsive to a combination of electrical impulses and arelay controlled by said selector, two transmission lines associated with said radio station and means including said relay for connecting said radio apparatus to said transmission lines alternately.

16. In a signalling system, a radio station comprising radio apparatus, a plurality of selectors at said radio station, a relay for and controlled by each selector, each of said selectors adapted to close a circuit for operating its respective relay in response to a definite combination of electrical impulses, a plurality of transmission lines associated with said radio station, each of said transmission lines associated with one of said selectors and a plurality of means each inized selector at said radio station, said solector responsive to a definite combination of electrical impulses of a definite polarity,

two transmission lines associated. with said radio station, said radio apparatus being normally connected to one of said transmission lines, said selector operable to disconnect said radio apparatus from said first mentioned transmission line and to connect said radio apparatus to the other of said transmission lines.

18. In a telephone system-comprising a plurality of radio stations, each of said radio stations, comprisingradio apparatus, and selective means whereby said radio apparatus can be connected to and disconnected from a trunk line, said means comprising a selector responsive to a definite combination of electrical impulses of a definite polarity, alternate radio stat-ions being equipped with selectors responsive to positive impulses, and intermediate radio stations with selectors responsive to negative impulses.

19. In a telephone system, a plurality of radio stations, a selector for each of said radio stations, whereby the radio apparatus can be connected to a trunk line, said selectors at alternate radio stations responsive to definite combinations of electrical impulses of positive polarity, and said selectors at in termediate radio stations responsive to definite combinations of electrical impulses of negative polarity; a control station connected to said trunk line, comprising inipulse sending devices for operating said selectors, each of said impulse sending devices being arranged to send out a definite com-. bination of impulses of one polarity followed by an impulse of opposite polarity.

20. In a telephone system, comprising a plurality of radio stations, a trunk line, a control station, means operable from said control station, whereby radio apparatus at said radio stations can be connected to and disconnected from said trunk line; a relay at each of said radio stations operable from said control station, whereby the transmitting apparatus and receiving apparatus at said radio stations can be alternately connected to and disconnected from said trunk line.

21. A signalling system comprising a plurality of way stations situated at intervals,

a transmission line multiply associated with said way stations, but normally out of communicative relation therewith, a listeningin circuit multiply associated with said way stations and normally-in communicative relation therewith, and selective means whereby said way stations can be individually put out of communicative relation'to said listening-in line and into communicative relation with said transmission line.

22. A signalling system comprising a plurality of radio stations situated at interval's, a transmission line multiply associated with said radio stations and normally out of communicative relation therewith, a listenin in line multiply associated with said radio stations and normally in communicative relation therewith, a control station jointly associated with said transmission line and said listening-in line, and means operable from said control station whereby said radio stations, individually, can be put into communicative relation-to said transmission line and out of communicative relation with said listenin -in line.

- 23. In a signaling system, a plurality of radio stations situated at intervals, a transmission line multiply associated with said radio stations, a control station associated with said line, means whereby a signal can be propagated from said control station over said line to any of said radio stations, selectively, and means including electromagnetic waves whereby said si al can be further propagated into the et er.

24. In a signaling system, a plurality of radio stations, a transmission line multiply associated with said radio stations, a control station associated with said line, means including said line whereby said control station can be put into communicative relation with said radio stations individually and means whereby signals can be transmitted from all of said radio stations to said control station simultaneously.

25. A signaling system comprising a plurality of radio stations situated at intervals in operable relation to a railroad, a transmission line multiply associated with said radio stations, radio apparatus carried by a vehicleon the tracks of said railroad, adapted to communicate with said radio stations, and means responsive to the relative osition signaling ap aratus associated with; said selector and w en so operated to preyent the operation, of the other of said selectorsassociated with saidlast mentioned signaling apparaius. l v i 1 28. I si a in s stem com risin a lurality of ra d io stgti ns situated 8 p a transmission line multiply associated with said radio stations, a control station associated with said line, means whereby messages at intervals,

may be transmitted in both directions over said line between any of said radio stations and said control station, selective means 0 erable from said control station whereli y said radio stations can be individually put into and out of communicative relation to sa1d line and means associated with said radio stations and said control station joint-- ly whereby an operator at said control stations both individually and collectively,and.

means operable from said control station whereby the operating wave length of said radio stations can be varied.

- 30. Ina signaling system, a plurality of radio stations each comprising radio transmitting and receiving apparatus, a line multiply associated with sa1d radio stations, a control station associated with said line, selective means operable from said control station whereby said radio stations can be individually put into and out of communicative rel@on to said line, means jointly associated with said radio stations and of said vehicle on said tracks where y sairL/said control station whereby an operator at radio stations can be individually put 'rfito and out of communicative relation to said line. no.

"" "26? A signaling system 'comprisin signal propagating means, a plurality o transmission lines associated with said signal propagating means, a plurality of selectors each associated with one of said transmission lines and operable to connect said transmission line to .said signal propagatin means.

and when so operated to preclude t e other of said selectors being operated.

27. In a signaling system, a plurality of signal stations, each comprising signaling apparatus and a luralit of selector s, a plus rality of transmission circuits m'ultlpl associated with said signal stations, eac "selector at each signal station operable to connect one of said transmission circuits to the said control station can receive signals from all of said radio stations simultaneously,

means operable from said control station whereby the transmitting and receiving apparatus at said radio stations .can be alternately put into and out of communicative relatlon to said line, and means operable from said control station whereby the operating wave length of said radio stations can be varied.

31. In a signaling s stem, a plurality of radio stations. situate at intervals in operable relation to a railroad, a line multiply associated with said radio stations, station associated wit-h said linefselective a controlmeans whereby said radio stations can be individually. put into and out of communicative relation to said line, radio appara-- tus carried by a'vehicle on the track oi said means whereby said radio stationscan be pulse sending means progressively connected to said line as said vehicle progresses, to the end that the radio apparatus carried by said veh1cle may be constantly in communlcative relation with one of the two of said radio stations with which it is in closest propinquity at any point on the railroad at which the vehicle may be momentarily situated. D

32. In asignaling system, a plurality 0t radio stations, a line multiply associated with said radio stations, an electromagnetic selector at each of said radio stations whereby said radio stations can be put into and out of communicative relation to said lme, a control station associated with said line, im-

for controlling said selectors, means for operating said impulse sending means, locking means for restralning said impulse sending means, electromagnetic means for releasing said locking means, and means for energizing said electromagnetic means.

33. In a system comprising a metallic transmission line and a plurality of radio stations situated along said line, the method of signalin which consists in transmitting electrical signals over the metallic circuit and thence into the ether from each of a plurality of radio stations progressively.

34. The method of signaling which consists in transmitting electrical signals over a metallic circuit to a radio transmitting station, propagating the signals from the radio transmitting station into the ether and subsequently transmitting other signals over the metallic circuit to another radio transmitting station, mentioned signals into the ether from the last mentioned radio transmitting station.

35. The method of signaling which consists in selectively connecting one of a plurality of radio stations to a metallic circuit, transmitting electrical signals over said cir cuit to said radio station and thence into the ether by electromagnetic Waves and subsequently selectively connecting another of said radio stations to said circuit, transmitting other signals over the circuit to the last mentioned radio station and thence into the ether by electromagnetic waves.

36. The method of signaling between two vehicles which consists in transmitting a signal from one of said vehicles through the ether to a radio station. thence propagating the signal over a metallic circuit to a second radio station and thence propagating the signal through the ether to the other of said vehicles.

' 37. The method of signaling which consists in selectively connecting each of a plurality of radio stations, one after another to a metallic circuit and transmitand propagating the last uann ting electrical signals over the metallic circuit and into the ether through the medium of said radio stations.

38. A signaling system comprising a radio station, a pluralit of transmission lines associated with sai radio station, said radio station normally connected with one of said lines and disconnected from the other or others of said lines, and automatic selective means operable to disconnect said radio station from the line to which it is normally ponnected and connect it to another of said mes.

39. In a signaling system, a plurality of radio stations, a transmission line, a control station, means operable from said control station whereby radio apparatus at said radio stations can be connected to and disat said radio stat-ions can be alternately connected to and disconnected from said transmission line.

' 40. In a system for signaling between moving vehicles, a transmission line situated along the vehicular route, means for transmitting signals over said line from one vehicle to another, said means including a source of high frequency carrier current on one vehicle, and means on the other vehicle for receiving the signals from said transmission line, a control station associated with said transmission line and means at said control station whereby an operator thereat can selectively establish channels of communication between the said vehicles.

41. A telephone system comprising a transmission line, a plurality of distantly separated radio transmitting stations situated along said line and operatively associated therewith, a plurality of control stations situated at intervals along said line, and means whereby voice signals and the like may be transmitted from any of said control stations over said line and thence into the ether from all said radio stations simultaneously.

42. In a telephone system, a plurality of distantly separated telephone exchanges, a transmission line interconnecting said tclcphone exchanges, means at certain of said telephone exchanges for connecting telephone subscribers lines to said transmission line, and a plurality of radio transmitting stations situated along said line and operatively associated therewith.

43. In a telephone system, a transmission line, a plurality of stations situated at distantly separated points along said line, a plurality of said stations each comprising a generatorof high frequency continuous wave oscillatory current, and means for modulating said oscillatory current in accordance with the voice signals transmitted over said line, and means at each of a plurality of said stations for transmitting voice signals over said line.

44. In a telephone system, a calling subscribers station, a called subscribers station, a line connected with at least one of said stations, a source of high frequency carrier current, automatic means operable over said line for selectively associating said source of carrier current with said line, and means including said source of carrier current and said line for transmitting speech between said subscribers stations,

45. In a signaling system, a plurality of radio stations, a plurality of control stations, a metallic transmission line or lines interconnecting said radio stations and said control stations, and means whereby signals can be transmitted from any of said control stations over said transmission line or lines and into the ether from all said radio stations simultaneously.

46. A signaling system comprising a transmission line, a plurality of radio sta tions each including a high frequency generator for propagating electromagnetic waves into the ether, said radio stations being situated at intervals along said line, and means remotely operable whereby said radio stations can be selectively connected with said transmission line.

47. A signaling system comprising a transmission line, a plurality of radio sta; tions situated at intervals along said line, a control station connected with said line, and means operable from said control station whereby said radio stations can be selectively connected with said transmission line.

48. A signaling system comprising a plurality of transmission lines, a plurality of radio stations situated at intervals along said line, and remotely operable selective means whereby said radio stations can be individually connected to any of said lines.

49. A signaling system comprising a transmission line, a plurality of radio stations situated at intervals along said line, each of said radio stations including a high frequency generator for the propagation of electromagnetic waves into the ether, automatic means for selectively putting said radio stations int-o operative relation to said line, and means whereby signals can be transmtted over said line to a selected radio station and retransmitted from said selected radio station into the ether through the medium of electromagnetic waves.

50. The combination in a telephone system, of a source. of high frequency carrier current for the propagation of speech, a telephone transmission line, and automatic switching means for operatively associating said source of carrier current with said line.

51. The combination in a telephone sys-' tem, of a plurality of sources 0 high frequency carrier current for the propagation of speech, a telephone transmission line, and automatic means forselectively and operatively associating said sources of carrier. current with said line.

52. The combination in a tele hone system, of a plurality of sources of high frequency carrier current for the propagation ofspeech, a plurality of transmission lines, and automatic selecting means for operatively associating any of said. sources of carrier current with any of said lines.

53. In a signaling system, a transmission line, a plurality of sources of high fre quency carrier current operatively associated with said line. and means operable over said line for varying the frequency of operation of any of said sources.

54. In :a telephone system, an operators position, an incoming line at said position, outgoing lines terminating at said position, means at said position for interconnecting said incoming line with any of said outgoing lines, a plurality of carrier current channels, a calledsubscribers station, and automatic means under the control of an operator at saidposition for extending a talking path from said incoming line to said called subscribers station, said talking path including one of said outgoing lines, said automatic means being o-perableto selectively and operably associate one of said carrier current channels with the outgoingv line included in the talking path.

55. In a telephone system, a calling subscribers station, 'acalled subscribers station, a line connected with at least one of said stations, a plurality of sources of high frequency carrier current, automatic means for selectively associating said sources of carrier current with'said line, and means including said line and a selected one of said sources of carrier current for transmitting speech between said subscribers stations.

56. In a telephone system, a calling station, a called station, a line connected with at least one of said stations, a source of high frequency carrier current, automatic means controllable from said 'calling stationflfor selectively associating said source of carrier current with said line, and means including said line and said source of carrier current for transmitting speech between said stations.

5 7. In a signaling system. a transmission line, a plurality of sources of high frequency carrier current operatively associated. with said line, and means operable over said line for varying the frequency of operation of any of said sources.

58, In a telephone system, a calling station, a called station, a line connected with at least one of said stations, 21 source of high frequency carrier current, an impulse sending device at said calling station, automatic means operable under the control of said impulse sending device for extending a s1g-- operable for selectively associating any of said sources of carrier current with said line, and means including said line and the selected source of carrier current for pr0pagating speech between said stations.

60. In a telephone system, a calling subscribers station, an operators position, a line from said calling subscribers station to said operators position, a called subscribers station, a trunk terminat ng at said operators position, means at said operators position for connecting said calling subscribers line with said trunk, a source of high frequency carrier current, and automatic means operable under the control of an operator at said position for operatively associating said source of carrier current with said trunk, and means including said line, said trunk, and said source of carrier current for propagating speech between said subscribers stations.

61. In a signaling system, the combination with a metallic transmission line of a source of high frequency waves, means operable over said line for connecting the terminals of said line with said source, means for propagating signals over said line to said high frequency source, and means for modulating the high frequency waves in accordance with said signals.

62. A signaling system comprising a transmission line, a plurality of radio stations each including a high frequency gen-- erator for propagating electro-magnetic waves into the ether, said radio stations being situated at intervals along said line, and means remotely operable whereby said radio stations can be selectively controlled.

63. A signaling system comprising a transmission line, a plurality of radio stations situated at intervals along said line, a control station connected with said line, and means operable from said control station whereby said radio stations can be selectively controlled.

64. In a signaling system, a transmission line, means for transmitting signals over said line, a plurality of stations situated along said line,'means at each of said stations for propagating high frequency signal waves, means for modifying said highfrequency waves inaccordance with signals transmitted over said line, and means remotely operable for individually selecting said stations.

65. In a signaling system, a transmission line, means for transmitting signals over said line, a plurality of stations situated at intervals along said line, radio transmitting apparatus at each of said stations operable to transmit electromagnetic waves in accordance with signalstransmitted over said line, and means remptely operable for individually selecting said stations.

66. In a signalin system, a transmission line, a plurality 0 stations situated along said line, radio transmitting apparatus at each of said stations, a control station associated with said line, means operable for transmitting signals from said control station over said line and thence into the ether from any of said first-mentioned stations individually, and means operable from said control station for individually selecting I said first-mentioned stations whereby communication may be established through the medium of said transmission line and the radio apparatus at the selected station.

67 In a signaling system for railroads, means for radiating high fre uency electromagnetic waves at a plura ity of points along a railroad track, an electromagnetic wave responsive device carried by a train on said railroad track, and means responsive to the position of said train on said track for controlling the actuation of said first means.

68. In a signaling system for railroads, a plurality of sources of high frequency electromagnetic waves situated at intervals along a railroad track, a train movin along said track, apparatus carried by sai train,

' tions through the medium of said metallic transmission lines, a plurality of se arated radio transmitting stations operative y associated with said telephone exchanges and means whereby a signal may be transmitted through the medium ofany of said telephone exchanges and a plurality of said radio stations conjointly and simultaneously.

70. The combination in a telephone system of a pluralityof telephone exchanges, telephone subscribers stations, telephone subscribers lines, a plurality of radio receiving stations, means whereby operators at said telephone exchanges may establish telephone connections with a plurality of said radio receiving stations contemporaneously whereby radio signals may be re- -ceived at said telephone exchan es, and

means whereby connections may e established at said telephone exchanges between said plurality of radio receiving stations and any of said subscribers lines whereby received radio signals may be transmitted to the subscribers stations.

71. A radio transmittin station, a remote control station, a meta ic transmission line interconnecting said stations, means whereby signalsmay be pro agated from said control station oversai transmission lines and then into the ether through said radio station, and means whereby an operator at said control station can control the operating frequency of said radio station.

72. In a system of communication, a plurality of telephone subscribers stations, a plurality of radio receivers, a telephone exchange, transmission lines, said subscribers stations, telephone exchange and radio receivers being interconnected by means of said transmission lines, and means whereby said subscribers stations may be connected with said ra'dio receivers individually and collectively. In witness whereof, I hereunto subscribe.

my name this 20th day of November, A. D.

CROSBY R. 'GAUTHIER. 

